脊髓Pellino1在瑞芬太尼诱导的大鼠痛觉过敏中的作用及机制

The role of spinal Pellino1 in remifentanil-induced hyperalgesia in rats and its mechanism

目的:观察脊髓Pellino1 (Peli1)在瑞芬太尼诱导的痛觉过敏中的作用及可能机制。方法:成年雄性SD大鼠随机平均分为6组(n=6):包括生理盐水组(S组)、瑞芬太尼组(R组)、生理盐水+scrambled shRNA组(S+shscr组)、瑞芬太尼+scrambled shRNA组(R+shscr组)、生理盐水+Peli1 shRNA组(S+shPeli1组)、瑞芬太尼+Peli1shRNA组(R+shPeli1组)。R组、R+shscr组、R+shPeli1组大鼠通过尾静脉连续输注瑞芬太尼4μg/(kg·min) 2 h,建立瑞芬太尼诱导的痛觉过敏模型;S+shscr组、S+shPeli1组、R+shscr组、R+shPeli1组于瑞芬太尼给药前连续3天鞘内注射shscr或Peli1sh RNA;分别采用机械缩足反射阈值(mechanical withdrawal threshold, MWT)和热缩足反射潜伏期(thermal withdrawal latency, TWL)评价大鼠机械痛敏和热痛敏;Western blotting法和RT-PCR法检测Peli1、Iba1、GFAP蛋白及m RNA表达;ELISA法检测TNF-α、IL-6、IL-1β。结果:与S组相比,R组瑞芬太尼输注后6 h、1天、3天MWT和TWL明显降低(P <0.001);与R+shscr组相比,R+shPeli1组大鼠瑞芬太尼输注后6 h、1天、3天MWT和TWL明显升高(P <0.05, P <0.001);与瑞芬太尼输注前相比,R组大鼠瑞芬太尼输注后6 h、1天、3天脊髓Peli1蛋白及m RNA表达显著升高(P <0.001);与S+shscr组相比,R+shscr组大鼠瑞芬太尼输注后1天Iba1蛋白及m RNA以及TNF-α、IL-6和IL-1β表达明显升高(P <0.001);与R+shscr组相比,R+shPeli1组大鼠瑞芬太尼输注后1天Iba1蛋白及m RNA以及TNF-α、IL-6、IL-1β表达明显降低(P <0.001)。结论:Peli1参与瑞芬太尼诱发的痛觉过敏,其机制可能与脊髓小胶质细胞激活及其炎症反应有关。

Objective: To observe the role of spinal Pellino1(Peli1) in hyperalgesia induced by remifentanil and its possible mechanism. Methods: Adult male SD rats were randomly divided into 6 groups with 6 rats in each group: saline group(S), remifentanil group(R), saline + scrambled shRNA group(S + shscr), remifentanil + scrambled shRNA group(R + shscr), saline + Peli1 shRNA group(S + shPeli1), remifentanil + Peli1 sh RNA group(R + shPeli1). The model of remifentanil-induced hyperalgesia was established by continuous infusion of remifentanil 4 μg/(kg·min) for 2 h in groups of R, R + shscr, and R + shPeli1, and intrathecal injection of shScr or Peli1 shRNA were performed in S + shscr, R + shscr, S + shPeli1, and R + shPeli1 groups for 3 consecutive days before remifentanil administration. Mechanical allodynia and heat hyperalgesia were evaluated by mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL). Western blotting and RT-PCR were used to detect the protein and mRNA expression of Peli1, Iba1, and GFAP. The expression of TNF-α, IL-6, and IL-1β were determined by ELISA. Results: Compared with group S, MWT and TWL were significantly decreased in group R on the 1 st day and 3 rd day after remifentanil infusion(P < 0.001). Compared with R+ shscr group, MWT and TWL were markedly increased in R + shPeli1 group on the 1 st day and 3 rd day after remifentanil infusion(P < 0.05, P < 0.001). Compared with baseline, the protein and mRNA expression levels of Peli1 in the spinal cord were significantly increased in group R at 6 h, 1 day, and 3 days after remifentanil infusion(P < 0.001). Compared with S + shscr group, the protein and mRNA expression levels of Iba1 and the expression of TNF-α, IL-6, and IL-1β in the spinal cord were obviously increased in group R at 1 day after remifentanil infusion(P < 0.001). In addition, compared with R + shscr group, the expression levels of Iba1 protein and mRNA and the expression of TNF-α, IL-6 and IL-1β in the spinal cord were significantly decreased in R + shPeli1 group at 1 day after remifentanil infusion(P < 0.001). Conclusion: Peli1 is involved in the process of hyperalgesia induced by remifentanil, and its mechanism may be related to the activation of microglia and inflammatory reaction in rat spinal cord.